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Destructo-Nookie: The protagonist beats up his love interest; she returns the favor. True Romance.
Evilutionary Biologist: Subverted. The world government genetically engineers everybody for maximum genetic perfection (or, at least, elimination of imperfection), except for a carefully guarded population of "control naturals," and strongly encourages particularly hopeful genetic matches, as between the hero and heroine. The subversion is that this is presented as entirely a good thing. This society is sometimes described as a "socialist" state but bears more in common with Technocracy. Everybody gets a small annual dividend from the output of the whole global economy as if it were a corporation in which all are stockholders; control naturals get a larger dividend, enough for a livable income, in compensation for their genetic inferiority and inability to compete with the average person.
It's an aversion that one of their prime tenets is 'you will not engineer anything into the human genome that isn't already there'; the "genetic engineering" is used only to ensure that two people having children have children with the best genetic combination that both parents' DNA could potentially have made on their own if the kid rolled all natural 20s in the genetic lottery. A past society that did use full-on genetic engineering to try and create perfect people, specialized to their jobs, is held up and lampshaded by characters in-setting as 'The History Of A Really Horrible Idea And Why We Don't Do That No More'. An attempt to revive that movement is done during the story by the villains of that chapter, and presented as an even more horrible idea.